1. Field of the Invention
This invention relates to a headlight assembly for a working vehicle, with light source units mounted in a pair of right and left openings formed in a body having a front frame and side frames bent and extending rearward from opposite ends of the front frame, the light source units including a pair of right and left main bulbs for emitting light forward, and reflectors for forwardly reflecting light from the main bulbs.
2. Description of the Related Art
Conventionally, as seen from U.S. Pat. No. 5,718,303, for example, a headlight assembly for a working vehicle includes a body attached to a vehicle frame, the body being in the form of a plastic molding with a high degree of freedom for molding. The headlight assembly further includes reflectors mounted in a pair of right and left openings formed in the body, and cover members fitted for covering the light radiation planes (front planes with respect to a moving direction of the working vehicle) and acting as a pair of right and left optical lenses. These cover members usually are formed of an acrylic resin that is hard and highly transparent.
However, according to the prior art noted above, the entire headlight assembly relies solely on the body for strength. To secure a high degree of strength for the entire headlight assembly, therefore, the body must be molded into a complex shape to have high strength, or must be reinforced such as by adding reinforcing members to the body. This leads to a complicated body configuration or addition of new reinforcing members. As a result, the headlight assembly has drawbacks of increased manufacturing cost and complicated construction.
The object of this invention is to provide a headlight assembly having high strength as a unit without entailing high manufacturing cost and complicated construction.
The above object is fulfilled, according to this invention, by a headlight assembly for a working vehicle having a body and optical units as set out at the outset hereof, in which a cover member is provided for covering at least a large part of the body, the cover member including a pair of right and left lens regions opposed to light radiating planes of the reflector units which forwardly reflect light from main bulbs acting as light source units, respectively, a front wall region interconnecting the these lens regions, and side wall regions bent and extending rearward from lateral ends of the lens regions, respectively.
In this construction, the cover member approximately C-shaped in plan view is joined to the body also approximately C-shaped in plan view, to cover, from front with respect to a moving direction of the working vehicle, the light radiating planes of the reflector units which forwardly reflect light from the main bulbs. As a result, the entire body is reinforced by the cover member, to secure high strength for the entire headlight assembly.
The cover member in the form of a single unit for covering the right and left light radiating planes from front requires a simplified assembly procedure, compared with a pair of right and left cover members provided for individually covering the right and left light radiating planes.
In a preferred embodiment of the invention, the cover member has horizontally extending ribs formed on bent portions of the sidewall regions. With this construction, the ribs increase the strength of the sidewall regions of the cover member. The increased strength of the sidewall regions contributes to stability of the cover member joined to the body.
In a preferred embodiment of the invention, the cover member similarly has horizontally extending ribs formed on the front wall region. These ribs reinforce the front wall region of the cover member, and particularly minimize possible bending of the front wall region of the cover member.
In a preferred embodiment of the invention, the front wall region of the cover member has a vertical width: L1 smaller than a vertical width: L2 of the lens regions to produce a feature in outward appearance. In this case, the front frame includes an upper beam and a lower beam extending horizontally, and each of the upper and lower beams includes portions corresponding to the lens regions of the cover member and having a smaller vertical width than a portion corresponding to the front wall region, to maintain balance in strength.
In a preferred embodiment of the invention, the reflector units having reflecting surfaces each formed polygonal to have a plurality of reflecting elements for producing a predetermined light collecting and distributing pattern, and the lens regions of the cover member each formed of a substantially single surface. In this construction, the reflecting surface of each reflector unit is formed polygonal, thereby dispensing with a need to form the lens areas of the cover member to have a complex shape, e.g. numerous convex lens surfaces.
The reflector units include a pair of right and left reflectors surrounding the main bulbs acting as headlights. The right reflector and left reflector may be formed separately or may be integrated.
An operation is required to deposit aluminum, for example, on inner surfaces of the reflectors to form reflecting surfaces. According to this invention, the right and left reflectors are manufactured independently of the body. In time of a reflecting surface forming operation, there is no need to perform a troublesome preliminary operation to mask the body, for example.
In a further preferred embodiment of the invention, the light source units further include right and left sub-reflectors for laterally reflecting light from sub-bulbs, the sidewall regions of the body being formed to transmit light reflected by the sub-reflectors. With this construction, when making a turn at nighttime, the vehicle can illuminate the turning direction beforehand for the driver to visually check, with ease, road conditions and presence or absence of obstacles in the turning direction. Further, since the working vehicle can illuminate sideways, the driver may visually determine conditions of a location for storage with ease when storing the vehicle into an unlit barn, for example. Moreover, the right and left side frames of the body approximately C-shaped in plan view are effectively used for the sub-reflectors for lateral illumination, and the right and left side wall regions of the cover member C-shaped in plan view are effectively used for sub-lenses for lateral illumination. This reduces the number of parts compared with the case of using separate members to form the sub-reflectors and sub-lenses.
Other features and advantages of this invention will be apparent from the following description of the embodiment to be taken with reference to the drawings.